Freshwater Fish Diseases, Algae Problems, and Tank EmergenciesThis is a place to chat about different ailments of freshwater fish, as well as tips on how to control algae, and other topics about keeping your fish tank healthy. If you're having problems keeping your fish healthy, or the fish don't seem to be well, of you have some other type of emergency, this is the discussion board to post in. Our community of members will promptly give you guidance.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast and simple so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
OR

I have a 15 gallon tank with a 20-50 gallon aquaclear filter on it that has about 17 fish and two snails in it. It was been set up for about two-three months now. I had very high ammonia and nitrates and nitrites in my tank for about two weeks. When I tested my water today at my work the ammonia was back into the safe level but my nitrates and nitrites were both still very high. Im not sure what is causing this or what to do about it. I havent lost any fish since this all started to happen but I lost about ten fish before since I set it up which I thought was weird. Also my tank was always cloudy right before this started happening but now it is very clear.

Is it the tank in your signature? That's a crazy amount of fish for such a little tank, even more so if it's only been running for 2-3 months... Your beneficial bacteria has no chance of keeping up with such a load, which is why you're seeing high levels on everything. It's completely falling behind. You need to either upgrade to a larger tank (at least a 30 gallon, preferably larger to allow room for the live bearer fry you'll likely be getting) and/or rehome some fish. Honestly the 6 guppies alone put you darn near full stocking levels for that 15 gallon...

I highly recommend you play with some numbers in the aqadvisor.com stocking calculator to get a rough estimate of how many fish you can keep in your current tank so you can figure out how many need to be rehomed, or so you can figure out what size tank you actually need for so many. You can alleviate the levels somewhat by doing large water changes every 2-3 days, but that's only going to be a temporary fix at best. Sooner or later you will lose fish if you don't rehome/upgrade.

I work at a petstore and everyone I work with said as long as i got a filter that at least is double my aquarium it was ok to put more fish then I really should have in the tank. Most of the people I work with tanks have more fish then they should have and there tanks are fine.

You can get away with it for a little while with double filter capacity, but it's not a long term fix. The whole reason overstocking works at pet stores is because the fish aren't staying there long term. Overstocking in moderation works long term when you have a double-sized filter and weekly 50% water changes, but you've gone way past that. Just to get an idea I plugged your setup into the aqadvisor calculator, and you're at the 224% stocking level, only 94% filtration for those species, and would need to do 60% water changes weekly to keep things healthy. That's EXTREMELY overstocked, not just a little.

Edit: Another thing to bear in mind... The type of tank you have is very poorly suited for overstocking. Overstocked tanks do better the more surface area they have for gas exchange, but in a column you have even less surface area than a standard 15 gallon. It's one big recipe for failure.

From your description in your 1st post it's pretty clear you are suffering from problems due to overstocking, your actual stocking levels would back that up. Similar problems in the first couple of months of setting up and deaths of fish could also have to do with the nitrogen cycle becoming established.

Quote:

Originally Posted by thenightgoddess

I work at a petstore and everyone I work with said as long as i got a filter that at least is double my aquarium it was ok to put more fish then I really should have in the tank. Most of the people I work with tanks have more fish then they should have and there tanks are fine.

I don't want to be rude or controversial so please don't take it wrong but pet stores are pretty famous for giving bad advice when it comes to fish so take what you are told with a pinch of salt until you learn who you can trust.

It is true that stocking is somewhat relative. Factors like a better filter, more/bigger water changes and live plants can allow you to maintain a slightly higher stocking level but the levels can only be pushed so high without it leading to disaster sooner or later. High nitrites means it's not working in your tank. Are you doing water changes? High nitrates can usually be helped with water changes.

Your ammonia dropped because your tank “cycled.” That means you have healthy beneficial bacteria. You can’t see the little buggers but they are essential to keeping your fish healthy and alive. They eat fish waste, they need oxygen like the fish, and they turn ammonia into nitrite and finally into nitrate. Depending on the kind of fish nitrate can be relatively safe, nitrite not too bad, ammonia lethal. Have you ever read a bag of lawn fertilizer at the hardware store? One of the main things in that it adds nitrogen to make the plants green. Nitrate is wonderful plant food. If you have an algae problem, high nitrate is probably why. The good news it for you this is very easy to fix. I recommend you get a plastic trash can that holds about half the water your tank holds. Fill it with tap water, use a little de-chlorinator, and if you want to really do it right add an air stone and maybe a heater. Let your water age at least a couple of days, a week is good especially if you put an air stone in it. Take out about a third to half of your tank water, use a hose and suck up the trash as much as you can, then re-fill from your seasoned water trash can. The more delicate species you try the more you will have to check the make-up water, but for the kinds of fishies you listed you should be fine as long as the temperature of the make-up water is close to what you take out. WARNING – DO NOT EVER CLEAN THE TANK PRISTINE… the fishies need the good bacteria and if you empty the tank and scrub it, you kill the bacteria and your fish may not make it through the “cycle” to get back to where you are now.
Technical PS… when you take out the water you not only take out the nitrogen, you take out the minerals from your tap water. As you add water to make up for evaporation you add more minerals. They build up just like the nitrogen. If you get a routine of making and changing water there aren’t any kinds of aquatic animals you can’t keep alive, just how much time and effort you want to dedicate. I have a 240 gallon discus tank with about 20 of the most friendly and precious fish anybody could ask for. I started out with guppies a long time ago.